As is well known in the art, in recent years, there is a demand for further thinning of various glass plates including glass substrates for a flat panel display, such as a liquid crystal display, a plasma display, an organic light-emitting diode (OLED) display, or a field emission display. Therefore, along with the demand, a so-called glass film that is thinned into a film is being developed. For example, as disclosed in Patent Literature 1, a glass film having a thickness of 200 μm or less has been developed.
Further, for example, as disclosed in Patent Literature 2, as a package form for the glass film, there is adopted a glass roll formed by winding the glass film into a roll. The package form utilizes a characteristic that the glass film has sufficient flexibility due to its thinness, and has an advantage that it is possible to save a space occupied by the packaged glass film.
In addition, for example, as disclosed in Patent Literature 3, the glass roll is supplied while being unwound, a functional film is formed on a surface of the glass film, and then the glass film having the surface on which the functional film is formed is wound again. Thus, the functional film is formed on the glass film using a so-called roll-to-roll method. In this way, only by unwinding the glass film from the glass roll successively, film forming processing can be performed on the glass film sequentially, which is convenient.